Detection of peanuts in food products by real-time polymerase chain reaction

Applicability of the method for the detection of peanuts based upon real-time 5'-nuclease polymerase chain reaction (PCR) was evaluated for the analysis of food products. The method involved DNA isolation by chaotropic solid phase extraction using the kit GeneSpin (GeneScan, Freiburg, Germany) and a real-time PCR of HIRD et al. (2003) with primers and a fluorescent probe oriented to arah2 gene. The following analytical parameters were determined for the method: inclusivity 100 %, exclusivity 100 %, detection limit 200 pg DNA corresponding to approx. 34 diploid (2C) genome copies, and a practical detection limit of 0.01 %, as determined on a set of model meat pates with defined peanut contents. The real-time PCR method was applied to a panel of confectionery products and most of the food samples were found to conform to the labelling of peanut contents however, some discrepancies were found. The presented real-time PCR proved to be a rapid, specific and sensitive method for the detection of peanuts in food products.